Internal-combustion engine



April 23,1929. BARRELL 1,710,083

INTERNAL COMBUSTION ENGINE Original Filed Aug. 21, 1919 5 Sheets-Sheet. 1

94 53 53 57 Q has 94 9 April 23, 1929. c 5 BARRELL 1,710,083

INTERNAL COMBUSTION ENGINE! Original Fild Aug. 21, 1919 Inven 1/01" 75 7 9 M/W lit ory 5 Sheets-Sheet 2 April 3, 1929. c. s. BARRELL I 1,710,083

INTERNAL COMBUSTION ENGINE Original Filed Aug. 21, 1919 .3 Sheets-Sheet. .5

Patented Apr. 23, 1929.

UNITED STATES CHARLES s BARRELL, OF BOSTON, MASSACHUSETTS.

INTERNALCOI!IBUSTION ENGINE.

Application filed August 21, 1319, Serial No. 318,861. Renewcd October 23, 1925.

(The invention to be hereinafter described relates to internal combustion engines, and more particularly to such engines olthe two cycle type.

1t ha been proposed to construct an engine of this type comprising a cyliinler containing primary and secondary pistons. The primary piston is connected by a rod and crank with the shait ot' the engine and the secondmy piston is operatively connected with a cam on said shait't. ,ilhe'construction is such that on the in-stroxe oi": the secondary piston, the fuel charge is drawn. into the space in the cylinder between the secondary piston and the head oi? the cylinder, and on the out-stroke thereof, the cha is transferred to the space between the pistons, where it is comln'essed and exploded to produce the power stroke of the primary piston. Then the next iii-stroke of the secondary piston serves to scavenge out the burnt gases from the cylinder through the exhaust port.

It has been proposed to provide valves in these -Jondary piston through which the fuel charge drawn into the cylinderby saidpiston may be transferred to the space between the pistons. Since these valves are necessarily exposed to the products of comliiustion of the i uel charge, they are liable to become carbonized and permit more or less leakage itron'i the space between the pistons to the space between the secondary piston and the head oi? the cylinder, and thence through the inlet valve to the carliiuretor and from said space thr-ougl'i the opening in the cylinder head through which the stem tor the secondary piston pr jects. Also it the inlet valve for adn'iittingr the fuel charge becomes carbonized and leaks, there is further liability of loss of power. Another object of the invention is to provide means for preventing leakage along the stem of the piston stem and past the inlet valve. Another object is to provide means to prevent back fire from the explosion space, backthrough the secondary pisl on. I

ihl'lOtllCl' object oi? the invention is to provide yielding means in the connections between the ondary piston and its actuating cam. for reducing shock and wear on the cam :trom the sudden change in direction of the secondary piston at the ends 0i its strokes.

Another object of the invention to provide means for cushioning the secondary piston it approaches the limit ot its outward stroke.

, Another object is to provide means to facilitate removal of carbon from the pistons. I

' Another object is to provide means to ad mit air into the explosion spacebetwcen the primary and secondary pistons to follow the burnt gases through the exhaust passage to prevent adulteration of fresh fuel charges tion through one of the cylinders of the en Fig. at on an enlarged scale is a vertical section through a portion of one of the cylinders;

Fig. 5 on an enlarged scale is a perspective view of a portion of the secondary piston, parts thereof being shown in section; and.

Fig. 6 on an enlarged scale is a plan of the secmidary piston. y y

The engine may have any number of cylinders, but in the present instance, two cylinders or units 1 and 3 (Fig. 1) are shown conveniently disposed at a V-angle with respect to' one another and mounted on and connected by a casing 5 provided with brackets 7 for sup] )ortingthe engine on the chassis of an autrunobile or other su 'iport. Since these cylinders or units are similar, a description ot one'will sutllce for both.

ilbecyliudor 1, "for example, may be provided with a head 9 (Figs. 3 and 4t) detachably secured thereto by screw bolts 11, the

walls of the cyliniiler and head being formed hollow to, provide the usual water jacket.

The cylinder contains a primary piston 13 which may be connected by a rod 15 with a crank 17 on the shaft 19 journalled in suitable bearings 21 in the casingh, referred to.

The cylinder also contains a secondary piston 23,, in the present instance formed of two partsfifi and 527 secured togethe-rby screws 29. The outer part of the piston may have a .flan 'e 31 adaoted to )ro ect into an annular the intake valve with respect to the secondary piston. This valve is located in the cylinder adjacent the head thereof in a position such that it is coveredby the secondary'piston when the latter is in its outermost position. To preventleahage of the gases of combustion from the space between the pistons outward along the inner wall of the cylinder to the inlet Valve and to the carburetor, thesecondary piston may be provided with suitable leak-preventing means, such, for example, as, packing rings 43 which will be at opposite sides ofthe inlet valve when the secondary piston is in its outermost position, as will be noted in Fig. 3.

On the in-stroke of the secondary piston,

a fuel charge will be drawn from the carburetor past the inlet valve into the space between the secondary piston and the head of the cylinders On the outward stroke of the secondary piston the fuel charge thus drawn in, is transferred to the space between the pistons. Suitable means may be 131:0", vided for this purpose,in the present instance of the invention, in the form of a phu'ality of spring-pressed puppet valves 45 mounted in and carried by the secondary piston,the construction being such that these valves will automatically remain on their seats on the iii-stroke of the secondary piston, but'will move from their seats on the out-stroke thereof to allow the fuel charge to pass into the space bet-ween the pistons. V

Next will be described means for actuating the secondary piston. In the present instance, this means comprises a stem 47 having one end thereof suitably connected to the secondary piston, this connection being preferably by a universal ointwhich may be in the form of a ball 49 seated in a socket formed in the parts 25 and 27 of the secondary piston. The stem 47 projects outward through the head of the cylinder, a suitable stuffing box 51 being provided to prevent leakage from the cylinder along the stem. Adjacent the outer end of thestein is a cross bar or member 53 connected to the outer ends of rods 55 which pass inward through suitableguidcs 57 and 59 projecting laterally from the head and cylinder. The inner ends of the rods 55 may be provided with studs having rollers 61 working in camways 63 in a cam 65. In the present instance of the invention, each cam comprises two parts 57 and. 69 detachably secured together by bolts 71, and having bosses 7 3 fast on the crank shaft 19, referred to.

The construction is such that opposed camways are, provided in the parts of the cam adapted to receive the rollers on the opposite ends of the studs carried by the rods 55, and the latter project through spaces 7 5 between cam parts. As a consequence, a strong cam construction is provided for elliciently reciprocating the secondary piston.

The camway comprises a portion 77 (F of uniform radius extending nearly through an arc of 180, a portion 79 of varying radius for rapidly producing the instrohe of the secondary piston, and a portion 81 for rapidly producing the out-stroke of said piston. The portion 77 meets the portions 79 and .81 through portions 83 which may be gradually curved to reduce friction between the rollers and the camway as much as possible. It will benoted that't he camway is located ecccntrically with respect to the crank shaft, and therefore, to avoid a greater mass of n'iaterial at one side of the cam than the other, recesses 85 (Fig. 3) are formed in the cam to produce a balanced construction which will have a uniform rotary motion.

While each of the cams, in the present instance, is formed of two parts containing opposed camways, it will be understood that in some casesa cam may be provided having a single camway. Also, in some cases a single cam may be provided for reciprocating the secondary piston if desired, instead of cams at the opposite sides of the cylinder as shown herein.

The secondary piston is caused to en! the head of the cylinder during the eitplo on of the fuel charge, so that the reactive force will be transmitted from the secondary ton to the head of the cylinder instead of to the cam or cams through the connections between the latter and t1 e secondary piston. The secondary piston will engof the cylinder while the cam follower relic s 61 are working in the portion a"? of the cant way having a uniform radius. Pre ably, the can'iway and the connections therefrom to the secondary piston are such that the latterwill be moved by the coin outward until it enga :thelwad of the cylinder. bv ito insure of said piston against sa' il head, ay portion 77 may be of a width sufficient to leave a space 8'? between thecani followers 61 and the outer wall of the camway, so that the force of the explosion press the piston against the head of the cylinder without interfcrence from the cznnway, and therefore, without shock t o. the lzuter. To further contribute to the ellicient seating of the secondary piston against the head of the cylinder for the purposes described, the bar 58, referred to, may be yieldingly connected with the piston stem il-7. To accomplish-this, in the present instance, said bar'has a hole receiving a portion of said stem, and coil springs 91 and 93 are confined between said bar and adjusting nuts 94 threaded'on the stem.

The construction is such that whenthe cam moves the secondary piston upward, the motion is imparted from the inner wall of the camwa-y to the followers and thence through the rods to the bar 53. The latter in turn will compress the coilspring 91 and move the stem 47 and the secondary piston outward until said piston engages the head of the cylinder. The spring 91 thus energized, will tend to press and maintain the piston against the head. a

On the in-stroke of the secondary piston the motion will be transmitted from the bar 53 through the coil spring 93 to the stem 17 and the secondary piston, and since on the outstroke oit'the secondary piston the motion is imparted thereto through the coil spring 91., these springswill serve to tend to relieve the. cam from shock in changing the direction of movement of the secondary piston at the ends of its strokes.

In some instances it may be desirable to valves l5 in the secondary piston become carbonized and leak. This means, in the present instance, comprises a conical projection 101 on the secondary piston adapted to tightly seat against a conical recess 103 in the cylinderhead, the angleof said projection and re cess being of sufficient degree to insure tight engagement thereof without wedging of the proj ection in said recess so as to interfere with ready movement of the piston away from the head. The seal thus provided is locatedbetween the valves 15 and the piston stem 47. As a consequence, any leakage past said valves will be unable to escape to and along said stem. To further contribute to the prevention of the leakage referred to, the piston and cylinder head may be provided with a conical projection 105 and a conical recess 107 similar to the projection and recess described, and located radially inward therefrom, although this second sealing means is not indispensable.

To'further contribute to prevention of leakage, the secondary piston may be provided with upstanding circular seats or rings 109 (Figs. 5 and 6) on its upper surface surrounding the valve ports and adapted to engage similar seats or rings 111 (Fig. i) on the innersnrface of the cylinder head. Preferably three valves are employed in the secondary piston, and since each valve is provided with ringsas described, thesecondary piston will seat against the cylinder head at three points. Thiswill tend to insure tight engagement of all three rings of the piston with all three rings of the cylinder head. To further prevent any possibility of such leakage, the piston may be provided with an upstanding ring 113 at the upper surface thereofencircling and outside of thethree rings for the valve ports, and be adapted to engage asimilar ring 115 onthe inner face of the cylinder head encircling all three rings on the cylinder head.

It is important that on explosion of the charge between the pistons there should be no back fire such asmight ignite the fresh fuel charge drawn in by the secondary piston between the latter and the cylinder head. Suitable means may be provided to prevent such occurrence, and in the present instance each of the valve ports may be covered by a gauze diaphragm 117' (Fig. 5) suitably secured to the piston. p I

To facilitate removal of carbon deposits on the inner faces of the pistons, two diametrical-ly opposed exhaust ports 121 (Fig. 1) may be employed, the construction being such that the pipe connections 123 for the exhaust ports may be removed, and then one can look through one of the exhaust ports while. a tool is inserted through "the opposite exhaust port and manipulated to scrape the carbon from the pistons; 7

After the explosion of a charge between the pistons, the secondary piston is moved quickly downward to scavenge or drive out the burnt gases. The rapid exit of said gases I from the cylinder will produce a partial vacuum therein. To insure a fresh unadulter ated new charge in the explosion space, an air admission port 125 may be provided in the cylinder at a point beneath the exhaust-ports, so that as the primary piston moves downwardly, it will first uncover the exhaust ports to allow escape of the burnt gases, and then fresh air may be drawn in through the air port by the vacuum and follow the burnt gases out through the exhaust port, thereby insuring the complete discharge of all burnt gases. lVhen the primary piston moves up ward, it will first close the air port and then close the exhaust ports. The secondary piston, however, is moved upwardly more rapidly than the primary piston, so that the fresh charge will be transferred from the space between the secondary piston and the cylinder head into the space between the two pistons,

and this fresh charge will not be adulterated by any residual burnt gases in the space be-' tween the pistons. I

To provide lubricant for thestem of the secondary piston, a grease cup 127 may be mounted on the cylinder head and feed lubricant to the portion of the stem which reciprocates thrdugh the, head. This lubricant may gravitate downward al ng the stem towarl the ball oi the universal joint at the lower end of the stem. The piston may have a circular groove 129 adjacent the stem to catch lubricant and guide the same inward toward the ball on the end of the stem.

A spark-plug 131 (Figs. 1 ant 3) may be connected to the cylinder at a oint to ignite the compressed luel charge between the pistons.

As shown herein, two cy i lders are provided, disposed at a t -angle, and one cam .may serve both cylinders, since a plurality oi followers may work on the same cam and haveconnections leading therefrom to the secondary pistons of the cylinders. While two cylinders are shown herein, it will be understood that the engine mi ht have four or, more cylinders, all served by the same cam it desired.

The construction of the caniway oi the cam for reciprocating the secondary piston is such that said piston is moved quickly downward awav from the head of the. cyliudcr and quickly back toward said head. The radii of progressive po nts of the camway for moving said piston down and up rapidly, vary considerably in len 'th until the piston almostreaches the head or the cylinder, and is, for example, about one-half inchfrom said head. The radii of progressive points on the camway in moving the piston through this final one-half inch distance, vary but slightly. As a consequence, the piston is slowly moved by the cam through this last one-halt inch distance to the head of the cylinder, and pounding of the piston against tae head of the cylinder is prevented. The pistonfis thus seated against the head of the cylinder, and the reactive force of the explosion is borne by the head'ot the cylinder anier than the connections between thesecondary piston and the actuating cam there- In operation, the secondary piston will be moved downward to draw a fuel charge through the inlet port into the space between the secondary piston and the cylinder head, and in the course of this movement will scavenge, out the burnt gases rcsultingfrom the previous explosion. Then the secondary pis ton will move upward and force the fuel charge thus drawn in past me valves t5 into the space between the pistons. The primary piston will follow the secondary piston in its up and movement and compress the fuel charge between them, said charge being then ignited, and causing thepower stroke of the prin'iary piston. During the explosion of the charge the secondary piston willreinain seated against the head of the cylinder, so

that the reactive force of the explosion will ,be transmit-ted from the secondary piston to the cylinder head, and not to the actuating cam therefor.

Certain features of the internal combustien engine disclosed-herein are made the subject oi a divisional application Serial No. 65,327, filed October 28, 1925. I I

t will beunderstood that the invention is not limited to the specific embodiment shown, but that various deviations may be made therefrom without departing from the spirit and scope of the appended claims.

What is claimed is: l

l. A two-cycle internal combustion engine, comprising, in combination, a cylinder, primary and, secondary pistons there in, shai'h'a crank and rod connecting said primary piston with said shaft, connections between said shaft and second' ary piston for reciprocating the latter, valve means for transferring a fuel charge from the enter to the inner side of said secondary piston, means independentof the valve means for preventing the gases of combustion from escaping through the valve means during an explosion.

2. A two-cycle internal combustion en giue, comprising, in combination, a cylinder, primary and secondary pistons therein, a shaft, means connecting said primary piston with said shaft, an inlet valve in said cylinder adjacent the head thereof covered by said secondary piston when at the limit of its outward stroke, and piston rings on said secondary piston at opposite sides of said inlet valve when said secondary piston is at the limit of its outward stroke.

3. A two-cycle internal combustion engine, comprising, in combination, a cylinder, primary and secondary pistons therein, a shaft, a crank and rod connecting said primary piston with said shaft, means for reciprocating said secondary piston including a cam termed to hold said secondary piston stationary during explosion of the Fuel charge, and an inlet port in said cylind r covered. by said secondary piston during said explosion, said secondary piston provided with means for preventing loss of pressure through said port.

i. A two-cycle internal combustion engine,

comprising Min combination, a cylinder. primary and sccondarv pistons therein, a shaft,

means connecting the primary piston with I said shaft to rotate the latter, an inlet valve for admitting fuel into the cylinder above the secondary piston, exhaust and air admission ports in said cylinder adapted to be uncovered successively by said primary piston during the explosion stroke thereof, a valve'in the secondary piston for allowing the fuel charge to pass from above the same into the space between the pistons, and means actuated by said shalt vfor reciprocating said secondary piston and havin provision for movinvt-he same down- D .L' t? ward to scavenge out the burnt gases and having provision for initiating upward movement of said piston to transfer the fuel charge throughthe piston valve into the space between the pistons'after the primary piston has covered the air admission port and c3;- haust port.

5. A two-cycle internal combustion engine, comprising, in combination, a cylinder, primary and secondary pistons therein, a shaft, means connectii said primary piston with said shaft to l( .ate thesame, means to admit fuel char s into the cylinder above the secondary pie 1, an exhaust port in said cylinder uncovered by the primary piston in the course of the power stroke thereof, means to admit air into said cylinder after the primary piston has uncovered the exhaust port, valve means for allowing the fuel charge to passfrom above the secondary piston into the space between the pistons, and means actuated by said shaft for reciprocating the secondary piston and having provision for moving the same downward to scavei'ige out the burnt gases through the exhaust port.

6. A two-cycle internal combustion engine, con'iprising, incombination, a cylinder, primary and secondary pistons therein, means for reciprocating the secondary piston, and an intake valve for adn'iitting fuel charges into the space between the secondary piston and. the cylinder head on inward movement of the secondary piston, said cylinder having a pair of exhaust ports located between the pietons when at their limit of approach and en abling introduction of a tool through one of said ports visible through the other port for the purpose of removing carbon from the ends of said pistons.

7. A two-cycle internal combustion engine, comprising, in combination, a cylinder, primary and secondary pistons therein, a shaft,

a crank on said shaft, a rod connecting the crank to the primary piston, a cam driven by said'shaft, and connections between the cam and the secondary piston, said cam having a portion of varying radius for moving the secondary piston to and from the cylinder head and a portion of substantial length of uniform 'adius, the latter portion being adapted to cause the secomlary piston to dwell against the cylinder head, and said connections including yieldable means to prevent injury to the cam or connections while holding the secondary piston against the cylinder head.

8. A two-cycle internal combustion engine, comprising, incombination, a cylinder, primary and secondary pistons therein, a shaft, a crank on ,aid shaft, a rod connecting said crank to the primary piston, a cam driven by said shaft, and. connections between said cam and the secondary piston, said cam having a portion of varying radius for moving ti 3 so:- ondary piston to and from the cylinder head and a portionof uniform radius for causing the secondary piston to dwell a substantial length of time in engagement with the cylindcr head, said connections including spring means for preventing injury to the cam or connections while holdingthe secondary pis- 'ement with the cylinder head. 9. A two-cycle ii'iternal combustion engine, comprising, incombination, a cylinder, primary and secondary pistons therein, a shaft, a crank on said shaft, a rod connecting; said crank to the prinuiry piston, a cam driven by said shaft, and connections between said cam and the secondary piston. said cam havinga portion of varying radius for moving the secondary piston to and from the cylinder head and a portion of uniform radius and substantial length for cane-ring the secondary piston to dwell in engagement with thecylinder head, said connections including spring means'for preventing injury to the cam or connections while holding the secondary pistoniu engagen'ient with the cylinder head. and means to vary the tension of said spring means. I I i 10. A two-cycle internal combustion engine, connprising, in combination, a cylinder, primary and secondary pistons therein, a shaft, a crank on said shaft, a rodconnecting said crank to the primary piston, a cam driven by said shaft, and connections between the cam and the secondary piston, said cam having a portion of varyingradius formoving the secondary piston to and from the cylinder head and a portion of substantial length for causing the secondary piston to dwell in engagement with the cylinder head, and said connections including yieldable means to prevent injury to the cam and connections as the secondary piston is moved into engagement with the cylinder head and away therefrom.

11. Atwo-cycle internal-combiistion engine, comprising, in combination, a cylinder, primary and secondary pistons therein, a shaft, a crank on the shaft, a rod connecting the crank to the primary piston, and means actuated by said shaft for reciprocating the secondary piston including a stem for the secondary piston, a spring, and a member operating; through the spring for in'iparting outward movements to said stem and secondarypiston.

12. A two-cycle internal conibustiol'i engine, comprising, in combination, a cylinder, primary and secondary pistons therein, a. shaft, a crank on the shaft, a rod connecting the crank to the primary piston, and means actuated by said shaft for reciprocatiing the secondary piston including a stem for the secondary piston, springs, and a member between and operating through the springs for i mparting inward and outward movements to said stem and secondary piston.

13. A two-cycle internal combustion engine, comprising, in combination, a cylinder,

primary and secondary pistons therein, a shaft, a crank on the shaft, a rod connecting the crank to the primary piston, and means actuated by said shaft for reciprocating the secondary piston including a stem for the secondary piston, springs on said stem, a member between and operating through said springs for imparting inward and outward movements to said stem and secondary piston, and adjustable means on the stem for varying the relation of the stem to said member.

let. A two-cycle internal combustion engine, comprising, in combination, a cylinder, primary and secondary pistons therein, a shaft, a crank on the shaft, a rod connecting the crank to the primary piston, and means actuated by said shaft for reciprocating the secondary piston including a stem for the secondary piston, a spring, a member operating through said spring for imparting inward movement to the stem and secondary piston, and adjustable means on the stem for vary ing the relation of the stem to said member. 15. A two-cycle internal combustion engine, comprising, in combination, a cylinder, primary and secondary pistons therein, a shaft, means connecting the primary piston with the shaft, an inlet port for admitting fuel charges to the cylinder, said port being covered by the secondary piston during com- 'pression and explosion of the fuel charges,

and means for preventing loss of compression through said inlet portduring compression and explosion of the fuel charges.

16. A two-cycle internal combustion en gine comprising, in combination, a cylinder, primary and secondary pistons therein, a shaft, means connecting the primary piston with the shaft, means actuated by the shaft for causing the secondary piston to reciprocate and seat against the cylinder head, and afuel inlet port at a side of the cylinder for admitting the fuel into the space between the secondary piston and the cylinder head, said. port being located to be covered by a side of the secondary piston when the latter engages the cylinder head, thereby to prevent loss of compression through the inlet port during compression and explosion of the fuel charges. V

17. A two-cycle internal combustion engine comprising, in combination, a cylinder, primary and secondary pistons therein, a shaft, means connecting the primary piston to the shaft, means actuated by the shaft for causing the secondary piston to seat against the cylinder head, and a fuel inlet port at the side of the cylinder, said secondary piston being constructed and arranged to prevent loss of compression through the fuel inlet port during compression and explosion of the fuel charges.

In testimony whereof, I have signed my name to this specification.

CHARLES S. BARRELL. 

